Originally posted by zebra100 To save me buying another transformer, could I get away with either using 1x 120VA transformer (low power I know, but I don’t listen loud anyway), or could I safely parallel the 2 transformers to give more power? What are the grounding options?

I understand you want to convert dual mono amp into stereo unit with a potentiometer at the input, hence the integraterd version.

If you connect two transformers in parallel, you will be getting more power only into low impedance loads, when single transformer couldn't before provide more power.

Otherwise there is not much gain in using transformers in parallel, it may actually degrade the sound.

If one 120VA transformer worked fine with a single channel, it might as well work fine with both channels.

Besides, if you are considering using 2 transformers in parallel, why not use them as previously, one per channel?

__________________www.audiosector.com
“Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it.” - JC

I was reading Peter's thread with great interest. I noted that several people have asked where to find toroids in England. I have found that rs-online sell a 160VA 2 X 25V for a total of £18-95. A very nice price. I have not tried one but you can find it at www.uk.rs-online.com The manufacturer is Nuvotem and the part no. is 0160P1-2-025. I hope this is of use. Barry

I will be soon building more serious LM4780 bridged amps for my personal use, so some guide will be posted here as well.

__________________www.audiosector.com
“Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it.” - JC

I've been reading around and it seems people recommend increased capacitance on the power rails. I've got some 2200uf caps that i was thinking of trying in the LM4780 kit, would this have any negative effect ?

also how do i rig the inputs for bridge mode ? i.e 2 chips in bridged mode left and right. The diagram provided with the kit shows two inputs for bridge mode. I'm abit confused.

The diagram included with kits shows 2 options: parts and connections marked in red are for parallel configuration only, those marked in green are for stereo or bridged setup: http://audiosector.com/lm4780%20amp.pdf

It is no problem to add larger caps; depending on a system they may bring improvement, but not neccessarily.

__________________www.audiosector.com
“Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it.” - JC

Neither Patek nor Integrated amp do not use any heatsinks. Copper bars and aluminum panels are sourced from Metal Supermarkets.

__________________www.audiosector.com
“Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it.” - JC